反应详情

Stir a mixture of (S)-3-aminopyrrolidine-1-carboxylic acid tert-butyl ester (10.4 g, 55.7 mmol) and 2,4-dichloroacetophenone (10.5 g, 55 mmol) in dry toluene (400 mL) at 110° C. for 48 h. Concentrate and dissolve the residue in methanol (160 mL), add sodium borohydride (3.37 g, 89 mmol) slowly and stir for 20 min. Add 1 N sodium hydroxide (200 mL) and extract with diethyl ether. Combine the organic layers, wash with water, dry (magnesium sulfate), concentrate and chromatograph on silica gel, eluting with 0:100 to 40:60 ethyl acetate:2-methylpentane to give (S)-3-[1-(2,4-dichlorophenyl)-ethylamino]-pyrrolidine-1-carboxylic acid tert-butyl ester (5.6 g, 28%). 1H NMR (300 MHz, CDCl3) δ 7.41-7.51 (1H, m), 7.34 (1H, s), 7.24 (1H, dd, J=8.38, 1.98 Hz), 4.21-4.36 (1H, m), 3.42-3.57 (2H, m), 3.21-3.33 (1H, m), 3.04-3.15 (1H, m), 2.88-3.03 (1H, m), 1.96-2.05 (1H, m), 1.63-1.72 (1H, m), 1.37-1.47 (9H, m), 1.30 (3H, dd, J=6.59, 1.51 Hz), MS (ES): m/z=359[M+].

1. concentrationConcentrate
2. dissolutiondissolve the residue in methanol (160 mL)
3. stirringstir for 20 min
4. extractionextract with diethyl ether
5. washwash with water
6. dry with materialdry (magnesium sulfate)
7. concentrationconcentrate
8. washchromatograph on silica gel, eluting with 0:100 to 40:60 ethyl acetate